"It was one of those classes that if you didn't pay attention from the beginning, you were going to be lost," Brooks says. "And I didn't pay attention from the beginning."

He's not alone. Brooks, a rising sophomore at Northern High School, says 20 of his friends joined him to retake algebra in summer school last month.

A few probably wouldn't have set foot in algebra class if they'd had a choice and would have settled for a less challenging math course. But they didn't have a choice; every freshman in Baltimore must pass algebra these days.

Once the sole concern of college-bound students, algebra is for everyone now. In Maryland as elsewhere, students will soon be denied diplomas if they can't pass an algebra test.

Since the 1990s, schools nationwide have quietly begun requiring the course for more and more students, hoping they'll develop skills for college and a changing workplace -- not to mention everyday life, with its computer spreadsheets and cellphone plans.

"The average person is going to have to be able to think through things pretty clearly, and a strong argument could be made that the rigors of algebra help," says Lynn Arthur Steen, a math professor at St. Olaf College in Northfield, Minn., and editor of the 2001 book Mathematics and Democracy.

Twenty-one states require students to pass algebra to graduate. Now they're prodding teachers and textbooks to reinvent it, stressing real-world situations while minimizing calculation and theoretical concepts that dogged students a generation ago.

"It's not the way we learned it," says Baltimore summer school teacher Valerie Stamper, a baby boomer who attended high school 30 years ago, when most algebra textbooks were formula-driven.

Stamper and many other teachers welcome the shift to more real-life problems, but some critics say it's not that simple. Schools, they say, are diluting algebra, making it almost unrecognizable and less useful for college-bound kids.

Just as teachers and parents in the 1960s clashed over "the New Math," they're now grappling with what some call "the New New Math." Based on standards developed by the National Council of Teachers of Mathematics, it emphasizes critical and conceptual thinking and practical problem-solving while de-emphasizing calculation and arithmetic skills -- a trend critics say undermines math performance in general.

"It would be like teaching Shakespeare in comic books," says Tom Loveless of the Brown Center on Education Policy at the Brookings Institution, a Washington think tank. "The content has been dumbed down."

Other critics, such as Jerome Dancis, a University of Maryland math professor, say the standards are "destroying math education in the United States."

In California, the first state to adopt the council's standards, math scores plummeted in the 1990s, but after a 1998 "counterrevolution" among math teachers brought new standards, Dancis says, scores rose.

Council president Cathy Seeley says it's not the standards that are failing kids; it's that not enough schools follow them faithfully. "Unfortunately, in the United States we're a little impatient. When something doesn't show long-term results in the short term, we tend to say, 'Oh gosh, it's not working,' and jump ship."

Algebra is a 4,000-year-old mathematical system that uses letters or other symbols to stand for relationships between numbers, as in the equation 2(x) + 1 = 7. In this case, x = 3; 2 times 3 plus 1 equals 7. A bedrock math course that most students take in middle school, algebra is often their first foray into abstract reasoning and multistep problem-solving.

The percentage of students taking it is rising, but U.S. students' math performance remains well below that of other industrialized nations. Although overall math scores have risen recently -- U.S. gains from 1995 to 1999 were seventh out of 23 nations -- U.S. eighth-graders still score below many others.

Observers point to watered-down standards as one problem.

"Too often it's pretend algebra and it's pretend 'real world,' " Dancis says. He says his own children, who attended high school in the 1990s, were taught about one-third less math than he was in high school in the 1950s.

Traditionalists have long questioned the council's standards -- West Virginia Sen. Robert Byrd in 1997 stood on the U.S. Senate floor and complained about the spread of "wacko algebra" -- and continue to fight against them.

State math supervisors who gathered in Utah last month to study state standards found that many were vague. Course contents in various states are "very disparate," says Gail Burrill, a former math teacher in suburban Milwaukee who now researches math and science at Michigan State University. The council and the supervisors plan to issue a report on state standards this fall.

For his part, Steen notes that calls to toughen standards are often led by parents who hated math in school but say today's schools aren't rigorous enough. "They dropped out of math at some point," he says, "but, by golly, they want to make sure their kids get the same experience."

Others say it's unfair to criticize schools, which are teaching algebra to students who would have been overlooked a generation ago.

Federal statistics show that the percentage of 13-year-olds taking algebra or pre-algebra has risen sharply, from 35% in 1986 to 56% in 1999. The percentage of high school graduates who have taken Algebra II also has risen, from 35.6% in 1982 to 64.3% in 2000. In many districts, it tops 90%.

"Thirty years ago, we only taught algebra to a select group," says Linda Antinone, a 19-year veteran math and physics teacher at Paschal High School in Fort Worth. "If you weren't college-bound, you didn't get algebra."

As with other fields, technology has changed the way math is taught. Teachers say this has helped open it up to students who would have taken less-challenging math a generation ago. Even students with poor calculating skills are now encouraged to take algebra -- they just use graphing calculators instead of slowly plotting points on a curve.

Stamper concedes that helping students who have limited basic skills is "our biggest hurdle."

On a recent morning in Baltimore, Brooks and his friends quietly worked through problems in a barely-air-conditioned room at Lake Clifton-Eastern High School.

"There's more teachers for algebra than for all the rest of the classes," says Brooks, a football player who wants to attend the University of Miami someday. He hopes a 20-day crash course will help him pass the second time around -- and expects to find out this week.

If he doesn't, it's "twilight school," until 6 p.m., in the fall.

At Hershey (Pa.) Middle School, virtually every student takes algebra, Principal Kevin Fillgrove says. A few take it as early as seventh grade; others wait until eighth. Struggling students take two years to complete the course, stretching the material over eighth and ninth grades.

"Sometimes it takes a little bit more to master things," he says.

Fillgrove, who taught math for nine years before becoming a principal, says attitudes have changed since he began his career in the mid-1980s. "Our expectations were lower for kids back then."

Several studies have shown that students who take algebra are more likely to succeed in college. One federal study, which followed a group of students for 13 years after their sophomore year in high school in 1980, found that the math they took in high school had the greatest influence on whether they earned a bachelor's degree. Passing a math course higher than Algebra II more than doubled the odds of earning a degree.

In 1967, a young Dustin Hoffman got a one-word bit of career advice from an adult in The Graduate: "Plastics."

"If you have to say one thing to a young person these days, it's not 'Plastics,' it's 'Algebra II,' " says Anthony Carnevale, a senior fellow at the National Center on Education and the Economy.

Others say schools are dragging their heels on getting algebra and other important courses to minority and poor students. Russlynn Ali of the Education Trust West, an Oakland advocacy group, notes that while algebra became a graduation requirement for California's high school class of 2004, schools sought waivers for about 14,000 students -- even after the state gave districts six years to prepare.

Many districts complained they didn't know about the requirements until it was too late. "We've made it a graduation requirement, but if we waive it away, we're waiving away good policy," she says.

Even advocates of the new algebra say there's work to be done. Burrill says textbooks are "thicker and fatter" with a lot of irrelevant material. A popular algebra textbook from 1970, for instance, had 460 pages; the 2004 edition has nearly 800 pages.

Students "could go for a long time and never get to very much algebra," Burrill says.

In another popular book, students studying functions and graphs are asked to "think about the weather and its effect on voters. What correlation would you expect between inches of precipitation and voter turnout?"

"I have to pick and choose what's best for my students," Antinone says. "Different states have different standards, so the textbook publishers are trying to produce something that will please everybody."